Screw jack



July 3, 1923. 1,460,799

A. l.. yJOHNSON S CREW JACK Find Feb. 5, 1922 2 sheets-sheet 1 July s,1923. 1,460,799

A. L. JOHNSON SCREW JACK Filed Feb. s, 1922 2 shee'ssheet 2 @and usefulScrew Jack, o'fwhich the follow-4 ring is a specification. l .Theprincipal objects of this invention are" to provide jack,l preferablyone of thev Paented July 3, 1923.

. ALVIN L. JOHNSON,y 0E WORCESTER, MASSACHUSETTS, ASSIeNoR 0EFORTE-EIGHT PER CENT To w. G oULDINe WARREN, 0E HOLDEN, NASSACHUSETTSANDFOUR PER f CENT To ALBERT E. EAY, 0E WORCESTER,MASSACHUSETTS.

SCREW JAC-K.-

Application inea February aicitizen of the United States, residing at?flVorcester, inthe county of Worcester and State of Massachusetts, haveinvented anew screw type,v with* a simplified operating mechanism; toprovide means whereby the` operator can shift the pawlin a simplied lmanner Sol as tochange the "direction of operation fot the jack; toprovide `means whereby he can do it by motion of the pawl" operatinghandle inthe same direction in which he ismoving it to operate Vthescrew; i Vand to provide thesecfeatures, without the addition of anymovable parts,thusy eliminatingfthe entire expense of applyingthe l pawlshifting elements that are commonly used. e c 7 v c y The invention alsoinvolves-the provision s of a pawl carrying arm in connection with anoperating handle so arranged that/the screw cany be raised by asubstantially hori- Y v ontal swinging motion .of the. arm and means forfrictionally holding the screw opv'erating gear to prevent 4its movingin .the

w showing vthe positions of the operatingpawl and the way in which it isshifted, e

handle at thesideof the jack land toprovide `wrong directionaccidentally@ i* Further objects and advantages of .the inventionwilljappearhereinafter,i A Reference is to behad to the accompanyingdrawings'in which-,- l

Fig,4 1 is a front elevation of a screw jack;

constructed in accordance with .this :inven` tion, parts being shown insection; f

Fig, 2 is a plan of thefsaihe; Fig. .3y is a central vertical se ontheline 3-3 of Fig-2;

.,Fig. Jr'isa transverse sectional View on' the ctional view a, 1922.v sSerial No. 533,971. u

vAlthough thejinvention isica'vp'able geni l eralV use, Thavev shownjitlas appliedfto a screw Jackof the type involving abase 1() and a casing1.1, preferably integral .with thean opposite pair ofvvertcal vgrooves.12.' The.

casing has 'atop 131-with a guide 14,constituting vertical continuation.ofthe cylindrical passage. In this cylindrical passage is shown the jackscrew'l'having a vrestfl onthe top. Neary the bottom` it is provided'Iwith 'a cross pin 17 extending'beyond the screw and intozbothjof thegrooves .12.,l This provides means for preventingthe rotation .of thescrewwhile, `perriiittiiig to Inoveup and down in the casing. L i

,On the screw threads 'ofthefscrew' I .bevel gear 18 restingon the topof the'lower part of, the jack casing- .and located' under the cover 13.This is, operated lby*` bevel Operating gear19 fixed to'a'zhorizontal.shaft` l 20 havingvazbearing on thevcasizng: 11. MTherotation of thev gearsrais'esfor"lowers'vthe screw 15 as'is'wellunderstoodin art. The parts so far deseribedfconstitute ,the

jack on .the market'and I .have chosenfto illustrate the invention asapplied t0"'this type of jack although can belused on Yother /t-ypes., f

y 'haveshownithe gear 19`as pinnedfby a main parts ofay well known'typeof .ScrewV soV f lpin 21 on the shaft 20 and lI have shown the `cover 13as' provided with, adownwardlyextending p'ortionl22 whichis'pr'ovidedjwith a bearing l.for the outer 'end ofthe Shaft 20.

This portionQO" flares outwardly preferablyk Ito form twoabutir'i'ents23v 24at oppo'.' vsite sides which serve an important`purpose ,as will appear. j On theend of "the Shaztt is v' a handwhee'l'f25 whchgcan; be used td roa coil spring 26 which` bears onthebottom tate the gears `and raise oi. lower the Screw. i

lIn the casing directly 'under the cover and i bearing on top of thegearlS I have placed 1 v l c i i exerta yielding pressure on the gearand prevent its rotating accidentally in the wrong direction,` 1

Swingingly mounted on the shaft 20 is a dependingarm This arm isshown ascomprising a front and backV plateboth pivot-ed n the shaft and betweenthem is a cross pin 31 on which is pivoted a double pawl 3?' haringtents/th 'for engaging the' circular `'rack 33 on the edge of the gear19. The pawl is shown as of V shaped construe# tion to provide twodivergent surfaces 34 .for` engagement with the conical endv "of aspring pin 35 located in the bottom of the.

arm A30. This spring pin automatically yields when the pawl is shiftedand autoinaticallyv engages the opposite suracesB/l to hold thepawlyieldingly in either of its positions. K

At the .bottom the arm 30 is provided with fa Curved extension 3.6 towhich is pivotally i connected by a pin 37 a rod or tube 38.l This i thetwo surfaces 34 there is a slight depresmakes an foperatinghandle. Butif it is den s'ired vto have valong handle I prefer. .to provide it'with a screw threaded coupling 39 and connect itwith an extension tube4Q. Any desired number of these can :be used and on the lastv .one is ahand grip t1 for operat- At the-end'rofithe V shaped point between sionft2. vThis isto permit of the setting of the pawl infneutral positionvand hold it @this .tifniel tofbe in neutral position.

there by entrance v.the point of the pin 35 into ,this depression. .i y

In .theiorperations'of .the device the jack can be handled in the mannerindicated in Fig. 1 in which the metal handle r35S-40 -is employed as acarrying device coming` .against the edge of xthe casing and holding thejack in y"upright position while it is being set under the `automobileor other devicevjwliich itisdesired to raise or lower.

.Thus .the Voperator does not have to get under the car. The Ipawl issupposed at Hav- . set'the' device in place, the'operator can swing thehandle 38-40 down to a nearlyv horizontal .posi-tion. Las indicated indot-ted linesy and operate the jackfrom a considerable distance. This isdone by pulling the handle towardfthe operator as far yas, it will `go'asv shownl in Fig. 6. The .result `of this pis .to bring .the curved end'43 of the pawl 32 A,into contact withy .one of Vvthe abiitinents 23.,Pressure applied .by pulling the lhandle j after these two parts comein contact viorces the pawl uover .into ,the position shown in cey fin.thatjpositionf Now ii` the ,handle pushedv OIzWard, in the directionindicated f6 .andlalso Figs.y .1 and 7,.

rhespiing .pin @when yieifiingiy -hoifis I :by i.the .arrow in Fig.Guthe .pawl y,ratches over the teeth 33 moving in .that direction, ust

v mittent motion as as soon as the operator swings the ar'mkk 30 back inthe direction indicated in Fig. 7, the pawl will positively engage theteeth of the rack as shown in that figure and pulll .the gear 19.with it.positivel'y'i.v ,These actions are due to the shape :of the teeth onthe pawl which is radial on the outside of each tooth and slanting ontheinsid'e.l The result of theinotionthus'described is to turn the gear18`in` thefdir'e'ctionufto raise l thescrew'l. -Now as long as theoperator continues to swing the handle back and Lforth horizontally andthus swingkthe arm and .not 4bringl it far enough forward or lback totouch" either of the surfaces 23 or 24, the screw l5 will be raised byan inter- When ,the operator is desirous to stopthe upward motion andstartr` the screwkdown;J all he yhas ,to do is push'the handle away fromhinrto its limit. This .resultsI *in bringing ythe parts tothepositionshown in Fig. '8 in which the pawl engages the abutment 2eandtlius shifts .from .the raising.

to the lowering position.A yThe `furtherreis" common in this. type fciprocationv ofthe handle and the `oscillaltion .of Vthe ar m results inturning the gears in the opposite direction andklowjen .ing ythe screw.This continue until theA .operator swings'the handle back to theposition shown in Fig. 6 and thus again shifts the paw-l.

It is .to bek understood that in order to shift I.the pawlgfthe operatorhas to move.

the handle and the ,swinging arm to the limiting position in thedirection contraryy to that in which it .isxexerting force to move theload. It is quite naturalfthat in pulling' the handle forwardto raiseC11? load he may bringit too -tar forward Kswinging the pawl upagainst-the.surface 230i the.

device. This Awill ,not shift-the pawl. Simiv In order tofshift thepawlldie. has

It will be seen therefore 'thatthe slii`fting of the pawl isy anextremely easy mat-v ter, in fact is vreduced to its simplest terms andyet ythere is .no realdanger vl'or a green. operator to accidentallyshift the pawlin the wrong direction. lWhile theoperation of the deviceis reduced to lthe simplest .terms7 vthe mechanism is also reduced inthe saine degree, for` nothing is required to Ashirt the pawl except.twog'fiir-ed wallsflocated in the right position.

The vjackv can be lifted and lmoved about in'an'upright positionbybringing 'the parts to' either of the positions shown in Fig. l. iv Thel'wall 44;"orjthe vedge a screw andmeansfor raisingit an'dlolwering it,comprising acgeargof a swinging of 'the yframe .preventf its tilting;l"y

The spring 26 is arrangedxto-beari onthe gear 18y to exertl alfrictional pressure vand -prevent this gear "being rotated acciden-vtally inthe wrong direction; The hand Wheel 25 can berotated to` raise`or .lower the screw when there is no load on itin accordance with theposition of the pawl.

' jack upv to the 'work fand* disengaging `it from the work `whenthe'operation'f'is 'corn-y -of'af'swingingarnf pivotedrvonythe'axisijoti vsaid gear,A a pawl .-pivoted-,on the larm and pleted. f

tion of the device involves thelocatio-n` `of the handle almoststraig'ht'out in the'irear for front and that-the'op'erator'is'freeftooperate the handle at-any desired height and' can work the jack' 'byasimple push and pull 'motio'no-f the handle toward and lfrom thejackinstead 'ofthehitherto uni. versal` oscillation of a handle yaboutan in accessible axis Thisfis animportantfea- 4ture of 'this yinvention'becanse of *the :ease

' 'of operation which Vvis entirely incomparable [with the usuallpractice;"'-Furtherxnore,a comparatively small bari or pipe can be' usedfor'the handlebecauseits operation.'

does not result in any bending stra-in,f:as.

does the'use of the' usual oscillatory handle.

The shifting of the pawl is accomplished in exactly vthe samemanner.""This doesaway withthe necessity of crawling underacar. -"forthis purpose and eliminatesallrincon-` f'venient and ldirty operatingV'a'rrz'ufig'ement in the form ofchains or thelike` whichare oftenemployed for'v thejlm'aniinila'tionl of iacks.

' Although I have illustrated onlya single vform ofthe inventionI amaware of the'y fact that modifications 'can be made thereinl l by any'person' skilled intheI art without; de-

parting f from the scope of therinventi'on' as.'- Vexpressed in'theclaimsf'fTherefore Idov l not wish'to belimited to lall the uses `andconstruction herein shown-fand described,-

but what I do claim is1-' rest, of a depending oscillatory arm, ineans:`comprising a pawl for ycausing theoscillaf tion 'of said arm' toj raiseor lower thefrest,

" restv` ofa dependingoscillatory'arnn means tionrof lsaid arm yto raiseor lower'the rest,

will shift the pawl intoa' position to' cause' the rest 'tobe' moved?inthe direction in It isto be -noted further'that thevv operar` ack, thecombination with 'a' work which it is ,positively moved @by-the; swing-.ing of the arm in that direction. Y 1

8.7*1In a screwijack, thefcombinationdwith to turn it inloppositedirectionsas the'arm l i, -ing two teeth .adapted .tovengagethefgarswings 'on its, pivot, andfmeans jfor'shi'ftj ing'y the pawlwhen thearlnisswung totsw` v y v having two opposite teeth-adaptedfto;;en

gage the gearzto turnit'., inoppositeidirecv i tions' as ,thel :armswings :onxits pivoter-fand `stationary means on thefaframeaforfshift-`a gear, .meansconnected withgthe gearffor` raising and lowering therest,--,of jas :pii'foted :i i l depending arm,a pawl movablyl mountedon said arm and having,t two teethyfone adapted to engagethelgear*onf'one: sid'e of the f arm. and .the other on 1 the .other sideof thearm in accordance; with:` `theyshifting:,4

of the pawl, whereby as fthe? arm. is. oscil- "lated onjitsy axisfitwillV rotate the gearin i leitherdi-rection in accordance witha theposil .tion of :the pawl, wand] a casing" .in which said j gearisslocated havingfxed-wallsorfi fAabutinentsin ai positiontobeffengaged-,by

the pawl when "the arm l g ijswung to?. iits y limitingv positionineither direction andgto shlftthe'pawl .when vso engaged;

6. 'Inria-jack,'the.combination1witha;rais-1p 4 inggand. loweringImeans? .comprisii'ig a i ytoothed wheelzmounted 'to rotate on'y ahorilzontal axis, of any arm mountedfto vsw-ing 'on saidj; axis andnorlnallycdependingtherey from,y a pawl pirotedionffsaid ar'm onen,.-`axis parallel with the yaxis of-fthe wheel and having two 'oppositeteeth yproje'cting therefromfonen'gagem'ent :withzthe teeth ofthe i'wheely'the teeth oftheupawlvbeingfinclined l. In a ]ack,vthecombination with'- a worlr` onv their 'inner' VsidesA to rallownthepawltokfv travel' over the Iteeth of the wheel whenfthewith'respectwtdtheftoothed wheel whenthe e e pawl teethyare"ing:engagement with they "WhGelf "U -if ijf 7; In a'jack,A thecombinationwith alfrais l ing and lowering: meansj4 ,comp'ri'singg:` acomprising a pawl for causing theoscilla- 1- ,A VG0A and /means "wherebylthe swinging the arm i in'either' direction to its limiting positiontoothed wheel, ofan yoscillatoryarm'7 a pawl 'being- ,inclined on their"adjacent sidesgV to fallow ,the pawl; t@ navel.; ever ,the testator ythel'wheel' when the arm moves in one direction, the-opposite surfaces`of'saicl teeth.

i "beingl substantially radial with respect to thetoothed wheel.when'the pawl teeth'. are

ini engagement. with' the wheel, and .cas-

\ the" arm is swung upwardly `agzfiinst .them i and force the pawl toswing-onits axis inwardly into engagement with-the teeth of the wheelltoreverse the operation of the 8. In screw'jaclnthe combination withv 'thescrew and'nieans forraising' and. low- 'vering it, comprising a gear, ofanosci'llatory varm" pivoted on the axis of said gear, a

double-toothedy paw'l pivoted .on the 1 arm y adapted',toz'engagerthe'gear to turn it, and

lstationary. means on the frame 'for shift- 4ing the pawl when the armis swung to its limiting position, said pawl having converging sidesonthe other side of itsA pivot,y and a 'spring lpin .'onsthe vhandle inposition to engage either o'fsaid sides tov holclthe pawl ineithervofits extreme positions l'in` U v .pivoted on' a horizontal axisat itsv upper -4 ayielding manner. f

`f451`v *.i of' v 'l engage to -yieldingly hold the 9. Inajack, thecombination with a. rest,

a gear, Vmeans connected with; the gear` yfor raising and 'lowering therest of a pivoted. arm, a pawl on said arm lhaving two opposite teeth,adapted to engage the'gear,

whereby `as the arm: is oscillated. on"`itsr axis it will rotate thegear -injeither direction 'in-'accordance 'with the position of thepawl,

and a casing in which said gear. is :located having means: adapted tobeengaged by the pawl when the armis swungto-l its limiting position in`either direction .forfshifting the pawl, Isaid pawl vhaving vconvergingsides,

rand a pointed spring pinf 'for engaging said* sides toyieldinglyholdthe pawl 'in l'either 1 extreme position, the pawlV also beingprovided with a smallfnotch in its Vextreme vertex which 'the pointofthe pin is adapted to tral position.v

10. in a screw j f ble-toothed? pawl' pivoted kon the arm adapted tion,and a handle pivoted to the bottom-.ref

-Jack by a longitudinal Iforward and back 11,.l Ina screwy jack,theicoinbination th'e vscrew and means for raising and lowering it,comprising a gear, of a swinging arm pivoted-on the axis of said `gear,a dou-ble-y ack, the vcombination with the screw 'and means for raisingVand Llowering it, comprising a gear, of. a swinging -arm pivoted' ontheaxis of said gear, .a dou- `toothed.pawlpivoted 0.11v the arm adapted toengagelthe gear. to turn it, stationary means on the frame for shiftingthe pawl when the army is swungto its limiting position, and a and'.adapted to be located in. substantially horizontal position to operatethe jaCk byfa longitudinalforward and back motion, said handlecomprising -a plurality of detachablev sections adapted to engage theedge o f said...

frame to hold the j ack in upright position gears for connecting saidgear with the screw, and afspring yieldingly engaging. one

of said .bevely gears for preventing yitsniovingaccidentally, ofa'swingingarm, ak pawl pivoted on the ,armahd haVlIlg tWO. @Seth adaptedto engage the' gear to turn it in opposite directions "as the armswings` on its pivot, and means for shifting the pawl when v the arm isswung to its limiting rpositQn. n

'13. In a jack, the combination? with' a movable load rest, of adepending arm end,.means connected with the arm for rais- -handlepivoted to the bottom of said arnfr` nected with the arm, and extendingfrom itsubstantially at the 'level of the lower end of the arm when inuse, for swinging the arm'baclr and forthto operate the load rest.

414.111 a jack, the combination with a frame and a load rest movablethereon, of f an -arin pivoted on said frame,4 means connected with`said arm for'cmoving the rest when the arm is swung back and forth.,and

means 'connected with the end ofsaid arm V.and extending therefrom forvibratingsaid arm to operate the n rest. y l. 15. In ajack, thevcombination. with a vframe Tand afload rest vertically movable thereon',of anarm pivoted `on said frame andadapted toassume a 'substantiallyvertical position xwhen'not in use, means connected with said armformoving they rest 'said arm and extendingtherefrom for vibrating saidarm vto operatethe'rest. i

16.111 a ack, the combination with a movablelload rest,- of-a dependingarm, means connected with the arm for raising and lowering the rest,means connected with the arm, and extending from' it substantially atthe level-.of the lower end of the arm when in use, for moving the armback'and forth to operate the load rest, and means forre- .versing thedirectionofmotion .ofthe rest,

the last named means being operable 'by said means'for movingthe arm. f

17; Ina` jack, the combinationv with. a

frame and a load rest movable thereon, of an arm pvoted on said frame,means connected with said arm for moving the rest When the arm is swungback and forth, means connected With the end of said arm and extendingtherefrom for vibrating said arm to operate the rest, the rst namedmeans comprising a ratchet and paWl mechanism, and means whereby theratchet and pawl mechanism Acan vbe shifted by said 10 vibrating meansitself to change the' directron of motion of the rest upon the contnua-`tlon of the operatlon of said Vibrating,

means.

* In testimony aHXed' my signature.v

whereof `I have hereunto 15 I

